Picosecond excite and probe nonlinear absorption measurements in CuCl quantum dots

We report nonlinear absorption around the Z3 exciton in CuCl microcrystallites embedded in a glass matrix. Our experiments are performed in a test-pump configuration with picosecond pulses at low temperature. In addition to a shift and a bleaching of the excitonic resonance, induced absorption on the high-energy side is found. The nonlinear index changes induced per exciton per unit volume of CuCl quantum dot could be determined by Kramers–Kronig transformations.